The theory of user-driven innovation comes from MIT professor Eric von Hippel, who proposed that when tools are placed directly in the hands of people who have the most pressing needs for answers, innovation happens, because there is no longer a need to transmit requirements from one person (or group) to another.

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The history of innovation bears out Mr. Jobs's theory.

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Its foray into autos raised concern about the driver distraction implications of its Terminal mode head unit device, an innovation that is right-on, in theory, but poorly executed.

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